Device for casting dental fillings



' Ap ril s, 1924;

J. A. 'H EIDBRINK DEVICE FOR CASTING DENTAL FILLINGS Filed Nov. 20. 1922 INVENTQR;

1.77%" A. HE/DBR/NK v V ATTORNEYS.

Patented Apr. 8, 1924.

. gpg STATES JAY A. HEIDBRINK, OF MINNEAP OLTS MI NNESOTA.

DEVICE Fore. oas'rnve pn v'rar. Funnies.

Application filed November 20, 1922. Serial No. 692,149.

To all whom it may concern:

Be it known that I, JAY A. HEIDBRINK,

a citizen of the United States, residing at Minneapolis, in the county of Hennepin' and State of Minnesota, have invented certain new and useful Improvements in Devices for Casting Dental Fillings, of which the following is a specification.

'My invention relates to devices for easting dental fillings. In making dental castings orinlays for use as fillings, it'is customary to make a wax model or pattern having the shape of the tooth cavity which is to be filled. The model after being removed from the tooth cavity is surrounded with what is known as investment material with a sprue rod attached to the model and extending outwardly through the investment mavterial, and after this material'- has become set the wax model is burned out or melted so as to be absorbed by the surroundingmaterial, and the sprue rod having been removed a matrix is thus formed for receiving the molten metal or filling material to form the inlay or casting which is to be placed in the'toothcavity. An object of my invention is to provide'a device for causing the molten material to completely fill the matrix so that the casting will have the exact'shape of the tooth cavity whichit is desired to fill. An object in particular is to provide a device of this character in which the material will be drawn into the matrix by suction exerted below the matrix.

. The full objects and advantages of my invention will appear in connection with-the detailed description, and the'novel features embodied in my inventive idea will be particularly pointed outin the claims.

"In the accompanying drawings which illustrate the application of my invention,

Fig. 1 is atop plan view of the device. .Fig.

2 is a view in vertical section on the line 2-.2 of. Fig- 1. Fig. 3 is a side elevational View looking at the right hand side of Fig.

2. .Fig. 4 is a view in vertical section on the line 4-4 of Fig. 1. Fig. 5 is a view in'hori- Zontal section on the line 55 of Fig.2.

As shown in the drawings, 1 provide a supportwhich includes a hollow bell-shaped base member 10 whichis provided with feet 12. The upper portionof the base member is reduced to form an annular shoulder 14: upon which rests the horizontal supporting member 16 of a clamping device, this horizontal member. being resiliently 'heldinpla'ce by a spring'lTengaged by a nut 18 screwed upona reduced threaded" portion 20 above which'isfa animator reduced threaded portion "upon which is screwed the lower end of a fiasksupporting member 24, the up f p ejr end ofwhi'c'h is'enlarged and'provided w th an annular flange 26 "within which a fflaslnM may loe'supported. This flask as shown: in Fig; 2 contains investment mater1al"1n which the cavity or-inatrix C has been forniedwhich'is to receive the casting material F. To one end of-the' horizontal "supporting membeflGfis pivoted a vertical arm'28 from the upper end 'of-which extends a horizontal clamping member 30 which as shownin' 1" is oval in shapesothat the two opposite andlonger sides of the oval portion may'res't up on the t op of the flask.

The 'fr ee endfor the clamping member is Ti 36 i which extends down into ailgul'arly spo ed p ssi sir ffis t e this p g way eing eda ts t v chamber40; The passage from the chamber flOto the passageway 38 is controlled by a needle alve"42' 'having a head l lby which the needle valve may be turned for ustment; "Connecte'd the" chamber 40 is a horizontalpassageway' 4G to" the outer end 'of which anipp1e48isattached; The pas- {sageithrojigh this'nipple is controlled by a ishiitoifivalveffio' andihe'quter end of the nipple is -adaptedfto receive the end of a flexible tubefor' conveying compressed air which may be delivered from any suitable source. A passageway '52 connects the perforation 36 with a. gauge 54 for indicating the degree of I vacuum ,in this perforation.

The operation and advantages of my in-' vention willnow be readily understood. A flask M containing investment material I J'ia' ving thereinthe 'matrix'or cavity C is positioned on the-supporting member 2 1 and clamped thereon asshown in Fig. 2 and the 'meltedfilling 'inatei'ial is placed at the top of the matrix. The operatorthen opens the valve permits compressed air to flowrpast the needlevalye" out of the downwardly inclined passageway 38, thereby causing suction downward through the perforation 36 and exhausting air from the matrix. The degree of vacuum produced in the perforation 36 may be regulated by turning the needle valve 42 and may be observed on the gauge 54. lrVhen the matrix has been completely filled, the valve is turned to shut off the supply'of compressed air and upon removal of the flask containing the filled matrix, the device is ready for use with another matrix. The resiliency of the spring 17 permits the clamp to adjust itself to the flasks in case these are not of uniform height. It is desirable that a constant degree of vacuum be maintained during the casting operation, and especially when the matrix is filled by suction exerted on the bottom of the matrix without the application of compressed airto the top thereof. Unless a constant degree of vacuum is maintained until the filling material has chilled and hardened, there will be a tendency for such material to pull up from the bottom of the matrix due to shrinking while becoming chilled. When a vacuum chamber is relied upon to produce the suction, there will be a gradual decrease ofthe vacuum due to the air drawn from the matrix. In my device, however, in which the suction is produced by a constant and uniform flow of compressed air, the degree of vacuum is maintained constant and this constant degree of vacuum may be regulated or varied as desired by adjusting the needle valve 40. The upward shrinking of the filling material is prevented by thusmaintaining constant during the casting operation the degree ofvacuum which causes suction to be exerted on the bottom of the matrix.

I claim:

1. A device for casting dental fillings comprising a support adapted to receive a flask containing a matrix to be filled, means for clamping said flask on said support, means for supplying compressed air to the device, means for' regulating the pressure of the compressed air which is supplied, and means whereby the escape of compressed air from the device will cause suction to be exerted on the bottom of the matrix.

2. A device for casting dental fillings comprising a support adapted to receive a flask containing a matrix to be filled, means for clamping said flask onsaid support, means for supplying compressed air to the device, means for regulating the pressure of the compressed air which is supplied, means whereby the escape of compressed air from the device will cause suction to be exerted on the bottom of the matrix, and a gauge for indicating the degree of vacuum produced.

3. A device for casting dental fillings comprising a support adapted to receive a comprising a base member flask containing a matrix to be filled, means for clamping said flask on said support, said support having a perforation which is underneath the flask when thus positioned and said support having a passage way connecting with the lower portion of said perfora tion, means for supplying compressed air to said passageway whereby suction will be exerted on the bottom of said matrix through said perforation, and a needle valve in said passageway for regulating the pressure of the compressed air.

4. A device for casting dental fillings comprising a support adapted to receive a flask containing a matrix to be filled, means for clamping said flask on said support, said support having a perforation which is underneath the flask when thus positioned and said support having a passageway connecting with the lower portion of said perforation, means for supplying compressed air to said passageway whereby suction will be exerted on the bottom of said matrix through said perforation, a needle valve in said passageway for regulating the pressure of the compressed air, and a gauge for indicating the degree of vacuum produced.

5. A device for casting dental fillings comprising a base member having a re vertical perforation, said base member containing a downwardly inclined passageway connecting with the lower end of said perforation, and means for supplying compressed air to said passageway whereby suc- 7 said flask supporting member containing a tion will be exerted on the bottom of said matrix through said perforation.

6. A device for castin dental fillings I liaving a reduced shouldered portion toward its upper end, a

horizontal clamp supporting member on said shouldered portion, a spring engaging the upper surface of said clamp supporting megiber, a nut on said base member above sai spring and resilientlyholding said clampsupporting member in place, a flask supporting member secured to said base member above-said nut and adapted to receive a flask containing a matrix to be filled, a clamping member pivoted to said clamp supporting member and adapted to engage shouldered portion engaging said the upper end of a flask when thus posiway connecting with the lower end of said tionecl, an arm pivoted to said clamp supperforation, and means for supplying com- 10 porting member, a nut on the upper end of pressed air to said passageway whereby sucsaid arm adapted to be screwed down upon tion will be exerted on the bottom of said said clamping member, said base member matrix through said perforation.

and said flask supporting member contain- In testimony whereof I hereunto affix my ing a vertical perforation, said base member signature.

containing a downwardly inclined passage- JAY A. HEIDBRINK. 

